#include<iostream>
using namespace std;
int f();

class c1{
int i;
		public:
c1(int i1){i=i1;};
friend int f();
};

class c2{
int i;
		public:
c2(int i1){i=i1;};
friend int f();
};

typedef class c1 C1;
typedef class c2 C2;

int f(){
		C1 o1(10);
		C2 o2(11);
		return o1.i+o2.i;
};



int main() {
	//class c1 o1(10);	
	C1 o1(10);	
//	o1=C1(3);	
	C2 o2(11);	
	//class c2 o2(11);	
//	o2=C2(4);	
	cout <<f() << endl;
	return 0;
};
